1. Field of the Invention
This invention relates to a hydraulically dampening bearing which has an internal tube, an external tube located at some distance from the internal tube, and a spring, or biasing means, inserted between the internal and external tubes. The bearing has sealed chambers filled with dampening fluid. The chambers are connected hydraulically to one another by means of throttle passages With this configuration, the spring, or biasing means, acts simultaneously as a load spring and sealing element.
2. Description of the Prior Art
German Patent Publication No. P 38 10 310.9, discloses a hydraulically dampening rubber bearing for uncoupling high frequency low amplitude, oscillations by means of the chambers. The bearing employs a recess which is sealed by a balancing membrane. However, it has been shown that during an increase in temperature of the bearing, the effectiveness of the dampening decreases. This disadvantage comes about through the temperature expansion of the dampening fluid and the rubber portion of the bearing. The expansion develops a pressure greater than atmospheric pressure in the chambers. As a consequence of this elevated pressure, the balancing membrane moves against the outer wall of the bearing and, thereby, becomes ineffective.